Scientists made a new hybrid peptide called LL-37Tα1 using yeast and showed it can grab and neutralize bacterial toxins (LPS) and cut down inflammation in mouse immune cells without harming the cells. This suggests the peptide could become a safe anti‑inflammatory or anti‑endotoxin tool, but it’s still early‑stage lab work.

This study pertains to the new approach for the development of hybrid peptide LL-37T&#x3b1;1 and its biomedical applications. A linear cationic hybrid peptide, LL-37T&#x3b1;1 was derived from two parental peptides (LL-37 and T&#x3b1;1) recognized as potent anti-endotoxin without any hemolytic or cytotoxic activity. We successfully cloned the gene of hybrid peptide LL-37T&#x3b1;1 in PpICZ&#x3b1;A vector and expressed in the <i>Pichia pastoris</i>. The recombinant peptide was purified by Ni-affinity column and reverse-phase high performance liquid chromatography (RP-HPLC) with an estimated molecular mass of 3.9 kDa as determined by SDS-PAGE and mass spectrometry. We analyzed the LPS neutralization by limulus amebocyte lysate (LAL) activity and the results indicate that the hybrid peptide LL-37T&#x3b1;1 directly binds endotoxin and significantly (<i>p</i> &lt; 0.05) neutralizes the effect of LPS in a dose-dependent manner. Lactate dehydrogenase (LDH) assay revealed that LL-37T&#x3b1;1 successfully reduces the LPS-induced cytotoxicity in mouse RAW264.7 macrophages. Moreover, it significantly (<i>p</i> &lt; 0.05) decreased the levels of nitric oxide, proinflammatory cytokines including TNF-&#x3b1;, IL-6, IL-1&#x3b2;, and diminished the number of apoptotic cells in LPS-stimulated mouse RAW264.7 macrophages. Our results suggest that the <i>P. pastoris</i> expression system is cost-effective for commercial production of the immunomodulatory and anti-inflammatory hybrid peptide (IAHP) LL-37T&#x3b1;1 and the peptide may serve as effective anti-endotoxin/anti-inflammatory agent with minimal cytotoxicity.